Prehospital delay is an important cause of out-of-hospital coronary mortality. To determine the effects of decision time delay in a patient population comprised mainly of blacks and the underprivileged, 74 consecutive patients with acute chest pain necessitating admission to the coronary care unit in a large urban hospital were studied. Delay time from onset of chest pain to the decision to seek medical care was markedly prolonged in patients with myocardial infarction (n = 24; mean time: 11.3 +/- 18 hours) as well as in patients with chest pain who did not develop myocardial infarction (n = 50; mean time: 20.5 +/- 26 hours). In addition, transfer time from the emergency room to the coronary care unit was likewise unduly long (mean time: 4 +/- 3.8 and 4.1 +/- 6 hours for patients with and without myocardial infarction, respectively). This study documents a significant delay in the decision time among patients with low socioeconomic status, mostly inner-city blacks, and in the transfer time from emergency room to the critical care unit in a large public hospital. These findings must be taken into consideration when planning strategies to improve the health-care delivery system to blacks and the underprivileged and further lend support to the practice of initiating thrombolytic therapy in the emergency room.